In the automotive industry, alternative materials to metal are considered for many components in automobiles. Synthetic materials such as plastics can provide improved characteristics over metals for some components. For example, materials which are reactively inert to fluids used in the automobile can provide improved corrosion resistance and longer life. Further, some plastic components have inherent sound deadening qualities when compared to metallic components and strength or impact resistance qualities that are advantageous.
Alternative materials to metals are considered also for use in complex parts that can be expensive to manufacture of metal by machining, casting and finishing/polishing or the like. Molding techniques to create the parts from nonmetals can be performed quickly and efficiently when compared to previously used processes for metallic parts. For example, a transmission manifold may require a plurality of ports on opposite sides thereof, which can be complex and costly to manufacture completely from metal, and manufacturing a body of plastic with metal inserts can provide advantages. Metal components also can be heavier than similar parts from nonmetals. Accordingly, alternative materials may reduce weight and increase operating efficiency for the automobile, in addition to reducing costs and expenses for supplying the part.
Some components, including for example a transmission manifold, must provide a ground connection therethrough in the completed assembly. If the manifold or other component is manufactured of non-conductive material, establishing a ground connection from one side thereof to an opposite side thereof can present difficulties. It is known that some of the ports on opposite sides of a transmission manifold, for example, can provide a continuous passage through the manifold between opposite sides thereof. A metallic insert used in the port can be used to establish a ground connection from one side thereof to the other side thereof. However, the required shapes for such inserts are complex and may have opposite ends in axial non-alignment. Accordingly, a one-piece metallic insert can be complex, difficult to manufacture and install and expensive.